Fire resisting article and method of making same



Patented Aug. 6, 1935 PATENT OFFICE FIRE RESISTING ARTICLE AND METHOD OF MAKING SAME John Fletcher, Kenmore, N. Y., assignor to Plastergon Wall Board Company, Buffalo, N. Y., a corporation of New York N Drawing.

Application October 10, 1933,

Serial No. 693,039

4 Claims.

treating the same with silicate of soda, but satisfactory results have not been obtained owing to the fact that silicate of soda is alkaline in character and sucha coated article will not hold a permanent coat of paint or enamel, because of the fact that a reaction occurs gradually between the paint and the silicate of soda, particularly if the silicate of soda is applied in a strong solution. If

a fabric or paper sheet is treated with a strong silicate of soda solution the strong alkali of the solution tends to discolor the paper or fabric. Attempts have also been made heretofore to utilize borates or phosphates as'fire proof materials, but they have not been very efficient due to the fact that they generate a non-combustible gas when heated, and the gas blows away leaving the fibrous material unprotected.

An object of this invention is to provide an,

improved, simple and inexpensive method of ren dering combustible and fibrous articles and sheets fire resisting or slow burning, and which will not destroy or injure theproperty of articles and sheets treated in this manner from receiving and permanently holding coatings of paints and enamel.

Another object of the invention is to provide an improved fibrous article which is strongly fire resisting, and which will receive and hold paint and enamel coatings, and which will be relatively inexpensive.

Another object of the invention is to provide an improved fibrous sheet which will be fire resisting and which will have maximum resiliency.

Another object of the invention is to provide an improved fire resisting and inexpensive wall board, and which may be painted or decorated in any desired manner:

Various other objects and advantages will be apparent from the following description of a practical application of the invention, and the novel features will be particularly pointed out hereinafter connection with the appended claims.

I have discovered that fibrous and other similar readily combustible materials andarticles may be made highly fire resistant or very slow burning by impregnating or coating the same with a chlorinated diphenyl resin. While diphenyls having different degrees of chlorination may all be used for this purpose and will impart to a treated article increased resistance to burning, I have found that those diphenyls having an intermediate range of chlorination are the most satisfactory for this purpose. The diphenyls having the lower degrees of chlorination are usually in liquid form and leave an oily feeling in the impregnated fibers. Those diphenyls having the 10 highest degrees of chlorination are diflicultly soluble and, therefore, difllcult to handle and apply to the fibers to be protected. I prefer to use those diphenyls which have a degree of chlorination in the intermediate range and which are 15 solid at ordinary room temperatures, and are also easily or moderately soluble in the known solvents of such diphenyls.

Solvents and dispersing agents for such chlorinated diphenyls are well known in the art, but 20 as a matter of record petroleum hydrocarbons, turpentine, carbon disulphide, furfural, acetone, chloro derivatives, and the coal tar solvents, that is solvents formed from coal tar products such as benzol, have been found to be very satisfactory as solvents for the chlorinated diphenyls. A readily vaporizable solvent is most satisfactory because of the ease with which it may be driven off after a fibrous article has been treated with the diphenyl in solution. One may provide a dispersionof the chlorinated diphenyl resins in water by using an emulsifying or dispersion agent such as triethanolamine, or stearic acid, for example. Thus, the chlorinated diphenyl is first suspended or dissolved in a liquid carrier and is then applied to the object to be treated so as to impregnate or coat the fibers of that object, after which the liquid carrier is driven on or removed, leaving a coating or deposit of the chlorinated diphenyl resins on the fibers.

If the chlorinated diphenyl is used in solution, the impregnated or coated article is subjected to heat or a current of air which removes the solvent, and if a dispersion agent is utilized, then the air and heat remove the moisture or dispersion agent. When a very porous body is treated to increase its fire resistance, it either may be thoroughly impregnated with the chlorinated diphenyl, or the porous body may be first caused to absorb a dilute solution of silicate of soda, and then after drying, the treated article is given a surface coating of a chlorinated diphenyl resin, which provides a completely fire resisting or fire proof body that will have a surface which will take and hold paints and enamels without danger of injury to the paints or enamel. The chlorinated diphenyl resins and the silicate of soda will not react on or mix with one another.

When paper, or cloth fabrics, are to be rendered fire proof or fire resisting it is sometimes desirable first to close the pores of the same with the chlorinated diphenyl resin, such as by applying a thin solution of 'the diphenyl to the sheet of paper or fabric, and then a highly dilute solution of silicate of soda may be applied to the previously treated but dry sheet of paper or fabric and the sheet is then dried. If the paper has close pores, such as is found in partially glazed paper, it is impossible to get sufficient resin into the pores to give the desired fire resistance in many cases, unless a thick resin is used in which case too much gloss and coating is provided for the sheet.

The thinner layer or coating of the chlorinated diphenyl resin gives considerable resiliency to the paper and also considerable resistance to combustion, and by then adding highly diluted or a thin coating of silicate of soda, an adequate fire resistant sheetis obtained without too much gloss and the thin or highly diluted coating of silicate of soda does not have suflicient alkalinity to discolor the paper or fabric or to prevent the adherence thereto of paint, enamel and printing inks. By using the diphenyl resin first, it provides a protection for the paper and the thin silicate of soda coating gives the additional necessary fire protection. It is impossible to mix the silicate of soda with the diphenyl resin solution and provide a single solution which may be applied to the porous articles to be treated, because the silicate forms lumps when added to the resin. If the silicate of soda is used alone in considerable concentration it tends to stiifen the fibers too much when used for fire proofing sheets of paper or fabrics.

Sheets of wall board, and particularly those that are commonly known in the trade as open pore wall boards, may be treated to render them fire proof or highly resistant to combustion, by thoroughly impregnating them with chlorinated diphenyl resins because the fibers of such a board are not highly compacted together and the diand the diphenyl resin provides a protective coating over the exposed silicate of soda so that paint and enamel decorative coatings will adhere firmly to the treated board and remain uninjured by the silicate. The silicate of soda and diphenyl resin together give the board maximum resistance to fire.

It will be understood that various changes in the details and materials, which have been herein described and referred in explaining the nature of the invention and its practical applications, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.

I claim:

1. A fire resisting wall board comprising a dry sheet of porous fibrous material with absorbed silicate of soda and coated with a readily soluble chlorinated diphenyl that is a solid at room temperatures.

2. A fire resisting article comprising a sheet of fibrous material impregnated with a readily soluble chlorinated diphenyl of such degree of chlorination that it is solid at approximately room temperatures, and having a dried surface coating of silicate of soda.

3. A fire resisting article comprising a body of porous fibrous material with dry, separately applied coatings of silicate of soda and a chlorinated diphenyl.

4. A fire resisting article comprising a body formed of combustible fibrous material, having its fibers impregnated with absorbed silicate of soda and then a coating of a solution of a clorinated diphenyl resin of an intermediate degree of chlorination.

JOHN FLETCHER. 

